Ramzan Kadyrov, Head of the Chechen Republic, in 2011 Wikimedia Commons MOSCOW (Reuters) - Suggestions that Russian politician Boris Nemtsov was killed by Chechen Islamists are nonsense designed to deflect suspicion from President Vladimir Putin, a colleague of the slain opposition figure said on Monday.

Investigators have charged two men including a former Chechen police official over the shooting of Nemtsov on Feb. 27, the most high-profile killing of a political figure since Putin took power in 2000. Three others have been arrested.

Chechen leader Ramzan Kadyrov said the ex-policeman, Zaur Dadayev, was a pious Muslim who had been angered by publication of caricatures of the Prophet Mohammad in French satirical magazine Charlie Hebdo.

Nemtsov had condemned an attack on Charlie Hebdo in which Islamist militants killed 12 people in January. But friends say they do not believe Islamist gunmen acting alone could have shot him dead within sight of the Kremlin, in one of the most closely guarded areas of Moscow, unless they had powerful and well-connected backers to help them get past the security.

These associates believe it was Putin who stood to gain from his killing, though Russian officials have denied involvement and the president has called it a shameful tragedy.

"Our worst fears are coming true," Ilya Yashin, the co-leader of Nemtsov's small liberal opposition party, said on Twitter late on Sunday. "The trigger man will be blamed, while those who actually ordered Nemtsov's killing will go free."

"Investigators' nonsensical theory about Islamist motives in Nemtsov's killing suits the Kremlin and takes Putin out of the firing line," Yashin added on Monday.

Nemtsov, a 55-year-old former deputy prime minister who became a vocal Kremlin critic, was shot in the back four times as he walked home with his girlfriend after dining next to Red Square. Dadayev and four other suspects, all ethnic Chechens, appeared in a Moscow court on Sunday.

Zaur Dadayev, charged with involvement in the murder of Russian opposition figure Boris Nemtsov, looks out from a defendants' cage inside a court building in Moscow, March 8, 2015 REUTERS/Tatyana Makeyeva

MODEL FIGHTER

Dadayev was a former deputy commander of the Chechen police's "Sever" (North) battalion which fought Islamist rebels in the region, where Russia has waged two wars to defeat separatists since the Soviet Union collapsed in 1991.

Dadayev's mother told Reuters her son could not have killed Nemtsov, and was being set up.

"He served his so-called motherland for 12 years. They threw him into the toughest areas, into the mountains to fight insurgents. He was a model fighter with a heap of state medals," Aimani Dadayeva told Reuters by telephone.

"And for them (the authorities) to use him for their own ends and to accuse him so harshly? ... I don't want anybody to use us for their own ends," she said, in tears.

Russian media reported on Sunday that police tried to detain another suspect at an apartment block in Chechnya's capital, Grozny. The suspect threw one grenade at police, then used a second to blow himself up, the reports said.

People march in memory of Russian opposition leader Boris Nemtsov, who was gunned down on Friday, Feb. 27, near the Kremlin in Moscow. Mindaugas Kulbis/AP Nemtsov was not widely popular in Russia outside the small, urban intelligentsia. But his supporters say he was a threat to the Kremlin because he was determined to expose official corruption and deceit.

In the days before he was killed, he was working on a report which, aides said, would allege that Russia was sending regular troops to fight in eastern Ukraine.

Moscow has denied any direct involvement in the fighting.

Prosecutors have charged Dadayev and another man, Anzor Gubashev, with involvement in Nemtsov's killing, and officials say Dadayev has admitted involvement. The three others who appeared in court have not been charged so far.

Chechen leader Kadyrov, who is loyal to Putin, said he knew Dadayev and described him as a true patriot.

"All who know Zaur confirm that he is a deep believer and also that he, like all Muslims, was shocked by the activities of Charlie (Hebdo) and comments in support of printing the cartoons," Kadyrov wrote on his Instagram account.

Nemtsov had defended the French magazine. He argued that Muslim clerics in Russia who had said it was wrong to print the cartoons were, in effect, justifying terrorism, and said prosecutors should investigate the clerics.